Wireless communication systems are experiencing an explosive growth in popularity. This increase in popularity has fueled a demand for wireless networks capable of providing high capacity, high quality, and power efficient voice and data communication. One such technology is multiple input, multiple output or MIMO. In a MIMO system, multiple antennas are utilized at each end of the point-to-point wireless link. This multiple antenna infrastructure allows known practical techniques to be utilized for improving spectral efficiency, link reliability, and power efficiency. This infrastructure, however, is also a major limiting factor in MIMO's widespread acceptance and deployment. While MIMO systems are able to provide higher throughput and reliability than other systems, their need for multiple antennas, and consequently, complex and costly RF chains, minimizes their suitability for certain applications.
In a recent patent application, cooperative communication techniques were disclosed which allow the advantages of MIMO to be achieved within systems using single antenna devices. The term cooperative communication refers to scenarios in which distributed radios interact jointly to transmit information in wireless environments. In effect, multiple single antenna devices cooperate with one another to appear as a single multiple antenna device. This allows the extraction of MIMO benefits in a distributed fashion. Cooperative communications or cooperative multiple access systems, however, do not allow the application of the known practical techniques currently used in MIMO systems to achieve spectral efficiency, link reliability, and power efficiency. Therefore, similar techniques to those used in MIMO systems, namely antenna selection and link adaptation, are needed for cooperative communication or cooperative multiple access systems.